help with working out how much wattage i need!

[Phil Starr]

21 hours ago, Wombat said:

So what is true?

 

On 23/04/2025 at 14:10, sky said:

ive seen a peavey minimega used that i might make an offer on, but with 1000w is that too much

Confusing isn't it?

 

The simple answer is that most amps nowadays are using pretty much one of two or three power amp circuits and just about every manufacturer offers a class D amp which gives 300W into 8ohms and 500W into 4ohms. They don't all sound the same but all of them will be loud enough into almost any but the smallest speakers and most speakers will be able to handle that power. The straighforward answer is that you can choose from any one of those amps and you wont break the 4x10's you are using in the rehearsal room. When you get to gigging any one of them will do the job with 90% of the speakers on sale. If you are using a Peavey 4x10 you don't need to use a Peavey amp, any brand will do. I like and own a Peavey Minimax whch has a good range of sounds but the best thing you can do is try a few of these amps out and see if you like them. We all have different tastes.

 

If you want a simple version of the technical stuff then try this. Some speakers are much louder than others with the same amp. This is measured in how many decibels of sound you can make with one watt. Most bass speakers will vary between 90db/ W (not very loud/efficient) to 103db/W (loud) Each extra watt can only add to that sound level, ten times the power adds 10db and doubling the power adds 3db, so a 100W amp with add 20db to whatever the one watt figure is and 200W will add 23db. To work out how loud a system will be you need to know the power of the amp and the efficiency of the speaker. Either on its own won't tell you anything, you need both numbers.

[Dan Dare]

On 03/05/2025 at 21:29, Phil Starr said:

The simple answer is that most amps nowadays are using pretty much one of two or three power amp circuits

 

This. Most class D amp heads use power modules from Hypex, IcePower, Pascal and similar. The modules are readily available, proven, reliable designs and it simply isn't worth amp makers designing their own/reinventing the wheel.

 

Most modules are at or around two power ratings - either 300w into 8 ohms/500w into 4 ohms or 500w into 8 ohms/700w into 4 ohms. Some amp brands inflate their power claims. I have a Carvin that claims 1000w, but it's no louder than my 700w Aguilar if you turn both up to the point that the clip light flashes. I wouldn't be surprised in the Peavey mentioned is the same.

 

Watts are cheap nowadays. All amps have a volume control, so unless funds are really tight, buy the more powerful version, be sensible with the volume control and don't over-drive your speakers (you'll know when you do because they will make horrible noises). Your sound will benefit from the additional headroom and when/if the time comes to up the size of your rig, the amp will still be up to the job, saving you from having to sell and upgrade it (which always costs).

[lemmywinks]

If you're worried about damaging loaned cabs then your overall volume and low end content are more important than watt rating, you can blow drivers with comparatively low power amps if you're an idiot - ask me how I know! Most micro amps will have some sort of built in HPF to remove extreme lows, I'd guess rolling off sharply at around 30hz or something like that. Just listen for speakers distorting (may be harder if you have a driven sound) and roll off the volume/bass as needed.

 

For something tiny which might get close-ish to your big amp the TC RH series or Orange Terror Bass might be worth looking at, they're small class D amps which are designed to sound closer to old school valve amps but go about it in different ways - the Orange uses a valve pre you can drive and the TC uses a digital approach which seeks to emulate valve compression/saturation. RH series are usually dirt cheap on the used market, should be able to grab an RH750 for £200-£250.